# Bell Alert Service Bulletin 407-04-66: Revision A - Rights: © Bell Textron Inc. Filed by the FAA in regulations.gov docket FAA-2013-0526; AD 2013-22-01 incorporates this document by reference. Not covered by OpenAirDocs’ CC0 dedication. - Document: [Bell Alert Service Bulletin 407-04-66](https://openairdocs.org/service-documents/bell/sb-407-04-66.md) - Title as filed: Bell Helicopter Textron ASB 407-04-66 Rev A - Pages: 14 - PDF: https://openairdocs.org/files/sha256/0c/6d/0c6d760de2e3dda34c4ca8ff4c1cfd2a37e2d5edf15aae88c454ce9785da62ec - Page: https://openairdocs.org/service-documents/bell/sb-407-04-66/file/0c6d760de2e3 ## Text Some pages are OCR from a scan. OCR can misread letters and numbers. Each page's text from the PDF; open the PDF at a page with #page=N. ### Page 1 ALERT SERVICE BULLETIN DATE REVISION NOTICE A Subsidiary of Textron Inc. Dec 01, 2004 TO: All Owners/Operators of Bell 407 Helicopters SUBJECT: REVISION “A” TO ALERT SERVI CE BUL LETIN 407-04-66: (FREEWHEEL AFT BEARING CAP 406-040-509-101, INSPECTION AND REWORK OF) Revision “A” to this bulletin mandates the replacement of the output shaft 406-040-517- 101 and sprag and retainer 406-040-580-103 for freewheel with discrepant aft bearing cap installed. AN APPROPRIATE ENTRY SHOULD BE MADE IN THE AIRCRAFT LOGBOOK UPON ACCOMPLISHMENT IF OWNERSHIP OF AIRCRAFT HAS CHANGED PLEASE FORWARD TO NEW OWNER ### Page 2 NO. DATE PAGE DATE REV ALERT SERVICE BULLETIN A Subsidiary of Textron Inc. AN APPROPRIATE ENTRY SHOULD BE MADE IN THE AIRCRAFT LOGBOOK UPON ACCOMPLISHMENT IF OWNERSHIP OF AIRCRAFT HAS CHANGED PLEASE FORWARD TO NEW OWNER 407-04-66 12-01-04 July 19, 2004 “A” 1 of 13 MODEL AFFECTED: 407 SUBJECT: Freewheel aft bearing cap 406-040-509-101, inspection and rework of HELICOPTERS AFFECTED: Model 407. Freewheel aft bearing cap P/N 406-040-509-101, serial number A-1833 thru A-1912. COMPLIANCE: PART I Upon receipt of this bulletin, determine if the aft bearing cap is affected. This applies to all spare aft bearing caps and freewheel assembly as well as those installed on the helicopter. PART II -NOTE- Engine cycle start average can be calculated by subtracting the actual engi ne start cycle count from the engine start cycles at which time the freewheel was installed and dividing by the freewheel time since new or time between overhaul. Example: 5000 cycles Total of actual engine cycle start - 3000 cycles Total of engine cycle start at the freewheel installation 2000 cycles Total of start cycle on freewheel assembly 2000 cycles Total of start cycle on freewheel assembly ÷ 1000 hrs Freewheel (TSN) or(TSO) 2 cycles/hrs Engine cycle start average ### Page 3 ASB 407-04-66 Page 2 of 13 For freewheel assem blies with less than 3 engine start cycles per hour on average and helicopters that are not exclusively used for training, ac complish PART II o f this bulle tin wit hin the next 50 flight- hours. PART III For helicopters exclusively us ed for training, and for freewheel assemblies with 3 engine start cycles or more per hour on average, accomplish PART III of this bulletin within the next 50 flight-hours. If the freewheel as sembly is removed for any reason, accomplish PART III of this bulletin. PART IV For freew heel assembly equipped with aft cap as described in the HELICOPT ER AFFECTED section, accomplish PART IV of this bulletin within the next 300 hours, but not later than 30 June 2005. A DESCRIPTION: Bell Helicopter has found that some fr eewheel aft bearing c aps are missing the lubrication channel int ended to allow oil flow into the a ft bearing support assembly. These caps may have been delivered on production aircraft or as spares. PART I of this bulletin gives instructions how to identify the affected aft cap. PART II and III of this bulletin provides proc edures required to r eturn the freewheel assembly to service. PART IV of this bullet in mandates the replacement of the output shaft 406-040-517- 101 and sprag and retainer 406-040-580-103 for freewheel with discrepant aft bearing cap installed. A APPROVAL: The engineering design aspects of this bulletin are transport Canada approved. ### Page 4 ASB 407-04-66 Page 3 of 13 MANPOWER: Approximately 0.5 man-hour is required to complete PART I of this bulletin. Approximately 3.0 man-hours are required to complete PART II of this bulletin. Approximately 16.0 man-hours are required to complete PART III of this bulletin. Approximately 16.0 man-hours are required to complete PART IV of this bulletin. Man-hours are bas ed on hands- on time, and may vary with pe rsonnel and facilities available. A WARRANTY: Owner/Operators of the affect ed helicopters who comply with the instructions outlined in this bulletin will receive a special 100% warranty credit for the replac ement parts contained in the “Required Material” section of this bulletin. Owner/Operators that comply with PART II of this A SB will rec eive $ 150.00 labor credit, Owner/Operators that comply with PART III of this ASB will receive $800.00 labor credit. An additional $100.0 will be issued for customers that elect local rework of the aft bearing cap. Purchase the required parts from an a pproved BHTI supply source. Submit a completed Maintenance Malfunction Info rmation Report (MMIR) to BHTI Warranty Department no later than 30 days after completion of this bulletin. MATERIAL: Required Material: The following material is required for the ac complishment of this bulletin and may be obtained through your Bell Helicopter Textron Supply Center. PART II Part Number Nomenclature Quantity 214-040-814-105 SLEEVE A/R (NOTE 1) 214-040-841-101 SEAL 1 406-040-509-101 AFT BEARING CAP A/R (NOTE 2) 406-040-532-103 BEARING A/R (NOTE 1) M83248/1-018 PACKING 1 M83248/1-021 PACKING 1 M83248/1-140 PACKING 1 MS24665-285 COTTER PIN 1 ### Page 5 ASB 407-04-66 Page 4 of 13 NOTE: 1. Bearing and sleeve replacement may not be necessary depending on the parts condition. 2. Aft bearing cap replacement may not be required depending on the option chosen by the operator. PART III Part Number Nomenclature Quantity 206-040-279-101 PACKING 1 214-040-841-101 SEAL 1 214-040-814-105 SLEEVE A/R (NOTE 1) 406-040-509-101 AFT BEARING CAP A/R (NOTE 2) 406-040-516-101 INPUT SHAFT A/R (NOTE 1) 406-040-517-101 OUTPUT SHAFT 1 406-040-530-103 BEARING A/R (NOTE 1 and 3) 406-040-532-103 BEARING A/R (NOTE 1 and 4) 407-340-533-101 BEARING A/R (NOTE 1 and 5) 406-040-580-103 SPRAG AND RETAINER 1 M83248/1-011 PACKING 5 M83248/1-016 PACKING 1 M83248/1-018 PACKING 1 M83248/1-021 PACKING 1 M83248/1-033 PACKING 1 M83248/1-034 PACKING 1 M83248/1-036 PACKING 1 M83248/1-140 PACKING 1 M83248/1-240 PACKING 1 M83248/1-238 PACKING 1 M83248/1-903 PACKING 1 M83248/1-906 PACKING 1 M83248/1-907 PACKING 1 MS24665-285 COTTER PIN 1 NOTE: 1. Replacement of bearing, input shaft, and sleeve, may not be necessary depending on the parts condition. 2. Aft bearing cap may not be required depending on the option chosen by the operator. 3. As an alternate, it is acceptable to use 406-040-530-105 or 206-040-206-001 in lieu of 406-040-530-103 bearing. 4. As an alternate, it is acceptable to use 406-040-532-101 in lieu of 406-040-532- 103 bearing. ### Page 6 ASB 407-04-66 Page 5 of 13 5. As an alter nate, it is acceptable to use 206-040-206-001 or 206-040-206-101 in lieu of 407-340-533-101 bearing. PART IV A Part Number Nomenclature Quantity 206-040-279-101 PACKING 1 406-040-517-101 OUTPUT SHAFT 1 406-040-580-103 SPRAG AND RETAINER 1 M83248/1-011 PACKING 5 M83248/1-016 PACKING 1 M83248/1-018 PACKING 1 M83248/1-021 PACKING 1 M83248/1-033 PACKING 1 M83248/1-034 PACKING 1 M83248/1-036 PACKING 1 M83248/1-140 PACKING 1 M83248/1-240 PACKING 1 M83248/1-238 PACKING 1 M83248/1-903 PACKING 1 M83248/1-906 PACKING 1 M83248/1-907 PACKING 1 MS24665-285 COTTER PIN 1 SPECIAL TOOLS: None required WEIGHT AND BALANCE: Not required ELECTRICAL LOAD DATA: Not affected REFERENCES: BHT-407-MM, Rev. 18 – 29 August 2003 Chapter 63, Main Rotor Drive System ### Page 7 ASB 407-04-66 Page 6 of 13 BHT-407-CR&O, Rev. 2 – 09 March 2004 Chapter 63-30, Driv e System Freewheel PUBLICATIONS AFFECTED: None affected ACCOMPLISHMENT INSTRUCTIONS: PART I: Identification of the affected aft bearing cap, 406-040-509-101 1. Open the engine access doors. 2. Locate the serial number (1, Figure 1) of the freewheel aft bearing cap (2). a. If the cap serial number is not list ed in the HELICOPTER AFFECTED section, no further action is required. Close the access doors and continue with Step 3. b. If the cap serial number is listed in HELICOPTER AFFECTED section, refer to the COMPLIANCE section and accomplish either PART II or III of this bulletin as directed. Contact Product Support En gineering Light Helicopters with the P/N, S/N, TSN, and TSO of the aft bearing cap and freewheel assembly. Product Support Engineering Light Helicopters Office: 450-971-6407 Fax: 450-433-0272 E-mail: pselight@bellhelicopter.textron.com 3. Make an entry in the helic opter Technical Records to show that PART I of the Alert Service Bulletin is completed. PART II. For freewheel assemblies with an average of less than 3 engine start cycle per hour and for helicopter that are not exclusively used for training 1. Remove the engine cowl ing and transmission fairin g assembly (BHT-407-MM, Chapter 53). 2. Remove the forward short shaft (BHT-407-MM, Chapter 65). ### Page 8 ASB 407-04-66 Page 7 of 13 3. Remove the aft adapter (5, Figure 2) and aft bearing cap (2) (BHT-407-MM, Chapter 63). 4. Remove bearing (1) from the aft bearing cap (2) (BHT-407-MM, Chapter 63). 5. Remove and discard the support assembly seal (3). 6. Inspect support assembly bearing (1) for condition (BHT-407-CR&O). Replace bearing if defective . 7. Inspect sleeve (4) for c ondition (BHT-407-CR&O). 8. Select from the following list, t he rework option deemed most suitable for convenience: a. Order a replacement cap assembly through your Bell Helicopter Spares supplier. Please note that limited assets are available to support this bulletin, and spares will be issued on a first come, first served basis. b. Locally rework the aft bear ing cap as shown in Figure 3. Use a vibrating stylus to identify locally-reworked cap assembly by adding letter "R" to the serial number on the cap. c. Provide the cap for rework to Bell Tennessee. This option permits the original cap to be reworked by Bell Tennesee, id entified with the rework letter "R" suffix to the serial number, and returned for installation. d. Obtain a reworked cap from the rotable pool availabl e through Bell Tennessee. This option will accept the rework c andidate in exchange for a reworked item from the rotable pool. Pl ease note that for this opt ion due to limited assets, a rework candidate must be supplied in adv ance of shipment from the rotable pool. e. For option c or d above, contact Bell Tennesee for advance scheduling at: Bell Helicopter Tennessee Textron 157 Industrial Park Road Piney Flats, TN. 37686 Office: 423-538-5114 Fax: 423-538-6198. 9. Install the support assembly bearing (1) and seal (3) into the aft bearing cap (BHT- 407-MM, Chapter 63). ### Page 9 ASB 407-04-66 Page 8 of 13 10. Install the aft bearing cap (2) and adapter (5) (BHT-407-MM, Chapter 63). 11. Install the forward short shaft (BHT-407-MM, Chapter 65). 12. Check the freewheel and transmission chip detectors for presence of metal contamination (BHT-407-MM, Chapter 63). 13. Install the engine cowling and trans mission fairing assembly (BHT-407-MM, Chapter 53). 14. Perform a 30 minute ground run as follows: a. Perform normal start as per Flight Manual. b. Operate the helicopter until it reaches 100% Nr then roll the throttle back to idle speed as you would do during normal operation. c. Repeat the above step one time every 2 minutes until the 30 minute ground run is completed. 15. Perform a serviceability check to the transmission and freew heel assembly (BHT- 407-MM, Chapter 63). 16. Make an entry in the helicopter Technica l Records to show that PART II of this Alert Service Bulletin is completed. PART III: For helicopters exclusively used for training, for freewheel assemblies with an average of 3 engine start cy cles or more per hour, or if the freewheel has to be removed for any reason. 1. Remove freewheel assemb ly (BHT-407-MM-6, Chapter 63). -NOTE- It is not necessary to remove wear sleeves from the forward and aft adapters unless they are damaged. 2. Disassemble the freewheel assemb ly (BHT-407-CR&O, Chapter 63-30). 3. Discard the sprag and retainer (7, Figure 2), the output shaft ( 10), and the aft seal (2). 4. Visually inspect the remaining freewhee l part details for condition (BHT-407-CR&O, Chapter 63-30). ### Page 10 ASB 407-04-66 Page 9 of 13 5. Select from the following list, t he rework option deemed most suitable for convenience: a. Order a replacement cap ass embly through your Bell Helicopter Spar es supplier. Please note that limited assets are available to support this bulletin, and spares will be issued on a first come, first served basis. b. Locally rework the aft bear ing cap as shown in Figure 3. Use a vibrating stylus to identify locally-reworked cap assembly by adding letter "R" to the s erial number on the cap. c. Provide the cap for rework to Bell Tennes see. This option per mits the original cap to be reworked by Bell T ennesee, identified with the rework letter "R" suffix to the serial number, and returned for installation. d. Obtain a reworked cap from the rotable pool availabl e through Bell Tennessee. This option will accept the rework c andidate in exchange for a r eworked item from the rotable pool. Pl ease note that for this opt ion due to limit ed assets, a rework candidate mus t be supplied in adv ance of shipment from the rotable pool. e. For option c or d above, contact Bell Tennesee for advance scheduling at: Bell Helicopter Tennessee Textron 157 Industrial Park Road Piney Flats, TN. 37686 Office: 423-538-5114 Fax: 423-538-6198 6. Assemble the freewheel assembly (BHT-407-CR&O, Chapter 63-30). 7. Install the freewheel assembly (BHT-407-MM-6, Chapter 63). 8. Make and entry in the he licopter Technical Records to show that PART III of the Alert Service Bulletin has been completed. PART IV: For freewheel assembly equipped with affected aft cap. A -NOTE- Sprag and retainer and the output shaft presently inst alled on freewheel affected by this bulletin, whic h have not run with a defective cap, may remain in service. ### Page 11 ASB 407-04-66 Page 10 of 13 1. For freewheel assem bly equipped with t he aft cap described in the HELICOPTER AFFECTED section of this bulletin, proceed as follow: a. If the freewheel ass embly is c urrently located in s pare st ock, continue with step 3. b. If the freewheel ass embly has had PART II of this bulletin complied with, continue with step 2. c. If the free wheel assemb ly has had PART III of this bulletin complied with, continue with step 8. 2. Remove freewheel assembly (BHT-407-MM-6, Chapter 63). 3. Disassemble the freewheel assembly (BHT-407-CR&O, Chapter 63-30). 4. Discard the sprag and retainer (7, Figure 2) and the output shaft (10). 5. Visually inspect the remaining freewheel part details for condition (BHT-407-CR&O, Chapter 63-30). 6. Assemble the freewheel assembly (BHT-407-CR&O, Chapter 63-30). 7. Install the freewheel assembly (BHT-407-MM-6, Chapter 63). 8. Make and entry in the helic opter Technical Records to show that PART IV of the Alert Service Bulletin has been completed. A ### Page 12 (OCR) ASB 407-04-66 Page 11 of 13 406-040-509 SERNO FWD V LEGEND 1. Cap serial number is located on the R/H side 2. Aft bearing cap (406-040-509-101) 03636001_IM Figure 1. Location of the lubrication channel and the serial number ### Page 13 (OCR) ASB 407-04-66 Page 12 of 13 LEGEND 1. Support assembly bearing (406-040-532-103) (1) 155600100 Support assembly seal (214-040-841-101) (1) Aft bearing cap (406-040-509-101) (1) Sleeve (214-040-814-105) Adapter (406-040-550-101) Fwd input shaft bearing (406-040-530-103) Sprag and retainer (406-040-580-103) Thrust bearing (407-340-533-101) Input shaft (406-040-516-101) 10. Output shaft (406-040-517-101) NOTE: 1. Support assembly bearing (1), support assembly seal (2), and aft bearing cap (5) are part of support assembly 406-040-500-119. 03636005_IM Figure 2. Parts affected by the missing lubrication channel ### Page 14 (OCR) ASB 407-04-66 Page 13 of 13 22-45 .188 IN R 1.059 IN (26.90 mm) (4.77 mm) 10.005 IN (0.13 mm) 1.126 IN (28.60 mm) +0.005 IN (0.13 mm). VIEW A SEE VIEW "A" FOR CUTTING DIMENSIONS SEE VIEW "C" FOR 3D VIEW 1.126 IN (28.60 mm) (26.90 mm) * 1.059 IN 3 SURFACE C SURFACE D 0.905 IN 0.0095 IN (22.99 mm) (0.24 mm) VIEW C SECTION B - B NOTES 1. Surface finish to be 125 u inch RMS /2. Machine scallop 1.126 inch (28.60 mm) +0.005 inch (0.13 mm) into bore. Length of scallop to be 0.905 inch (22.99 mm) ‡0.010 inch (0.254 mm) from the surface C. /3. Machine scallop 1.059 inch (26.90 mm) ‡0.005 inch (0.13 mm) into bore. Scallop to be 0.0095 inch (0.24 mm) ‡0.0025 inch (0.06 mm) below surface D. 4. Break all sharp edges. 03636003_IM 5. Machine scallop radius. 020 inch maximum 2 places Figure 3. Instructions required to modify the aft bearing cap 406-040-509-101 --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain, except the copies of manufacturers’ service documents, which belong to their rights holders.